Video-EEG monitoring of paroxysmal events in the elderly

EEG and semiology in the elderly: A systematic review

INTRODUCTION

The prevalence and incidence of epileptic seizures and epilepsy increases among the elderly. Epileptic seizures in older people remain often unreported and undiagnosed, contributing to incorrect or delayed treatment. The goal of our review paper is to increase awareness of seizures in the elderly, to improve the diagnostic process in this growing population.

METHODS

We present a systematic review of the literature on EEG findings and seizure semiology among the elderly according to the PRISMA statement. One hundred and two original studies were included and findings were divided in four groups: EEG among elderly without seizures, EEG among elderly with seizures or epilepsy, semiology, and status epilepticus.

CONCLUSIONS

EEG abnormalities are found in approximately half of the geriatric population referred to routine EEG. Slowing (both focal and diffuse) is the most common finding among seniors with and without seizures. Interictal epileptiform discharges (IEDs) are likewise seen among healthy seniors, which reduces their specificity as biomarker for epilepsy. Focal onset seizures prevail among the aged. Generalized seizures are uncommon, starting usually earlier in life but exacerbating in later years. Motor phenomena are less frequently seen than among younger individuals. Seizures are mainly characterized by impairment of awareness, disturbed cognition and confusion, both ictally and postictally. Unresponsiveness may occur during non-epileptic events too, which further challenges seizure recognition. Epilepsy and dementia are bi-directionally related: dementia carries an increased risk of developing epilepsy and vice versa. Up to 45 % of the aged with new onset seizures present with status epilepticus (SE). SE among the elderly is more often focal motor; non-convulsive status epilepticus (NSCE) constitutes 10-25 %.

Minimum standards for inpatient long-term video-EEG monitoring: A clinical practice guideline of the international league against epilepsy and international federation of clinical neurophysiology

The objective of this clinical practice guideline is to provide recommendations on the indications and minimum standards for inpatient long-term video-electroencephalographic monitoring (LTVEM). The Working Group of the International League Against Epilepsy and the International Federation of Clinical Neurophysiology develop guidelines aligned with the Epilepsy Guidelines Task Force. We reviewed published evidence using The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. We found limited high-level evidence aimed at specific aspects of diagnosis for LTVEM performed to evaluate patients with seizures and nonepileptic events (see Table S1). For classification of evidence, we used the Clinical Practice Guideline Process Manual of the American Academy of Neurology. We formulated recommendations for the indications, technical requirements, and essential practice elements of LTVEM to derive minimum standards used in the evaluation of patients with suspected epilepsy using GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Further research is needed to obtain evidence about long-term outcome effects of LTVEM and establish its clinical utility.

Minimum standards for inpatient long-term video-electroencephalographic monitoring: A clinical practice guideline of the International League Against Epilepsy and International Federation of Clinical Neurophysiology

The objective of this clinical practice guideline is to provide recommendations on the indications and minimum standards for inpatient long-term video-electroencephalographic monitoring (LTVEM). The Working Group of the International League Against Epilepsy and the International Federation of Clinical Neurophysiology develop guidelines aligned with the Epilepsy Guidelines Task Force. We reviewed published evidence using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statement. We found limited high-level evidence aimed at specific aspects of diagnosis for LTVEM performed to evaluate patients with seizures and nonepileptic events. For classification of evidence, we used the Clinical Practice Guideline Process Manual of the American Academy of Neurology. We formulated recommendations for the indications, technical requirements, and essential practice elements of LTVEM to derive minimum standards used in the evaluation of patients with suspected epilepsy using GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Further research is needed to obtain evidence about long-term outcome effects of LTVEM and to establish its clinical utility.

Diagnostic Performance of the Electroencephalogram in the Elderly Manifesting With Episodes of Unresponsiveness

This study aimed to determine diagnostic performance of the EEG in diagnosing seizures and to ascertain risk factors associated with seizures in the elderly presenting with episodes of unresponsiveness compared with younger patients. This is a cross-sectional study. Only EEGs requested with indication of transient unresponsiveness (TUR) were included. Patients were divided into 2 groups, younger (aged 18-49 years) and elderly (aged >60 years). The EEG was an index test. Reference standard, independently verified by 2 board-certified neurologists, was a clinical diagnosis of presence or absence of epilepsy/probable seizures. Univariate and multivariate analyses were performed to ascertain associated risk factors for epilepsy/probable seizures. Among 2187 total EEG recordings, 244 (11.16%) recordings were requested with indication of TUR. A total of 156 patients (50 younger and 106 elderly) were recruited for analysis. Prevalence of epilepsy/probable seizures in patients with TUR was 26.9%. Prevalence of interictal epileptiform discharges was 16% in the younger and 12.3% in the elderly. Overall diagnostic performance was poorer in the elderly. Associated risk factors for having seizures were presence of intermittent slow waves in the younger and presence of positive motor signs as well as presence of nonepileptiform abnormalities in the elderly. Prevalence of seizures and interictal epileptiform discharges was low in the elderly who manifests with TUR. Overall diagnostic performance of the EEG in diagnosing seizures was poorer in the elderly mainly due to low sensitivity. When we encounter patients with TUR, thorough and detailed history is still a mainstay of a diagnosis of seizures, not the EEG results.

Dual diagnosis of epilepsy and psychogenic nonepileptic seizures: Systematic review and meta-analysis of frequency, correlates, and outcomes

Comorbid epilepsy and psychogenic nonepileptic seizures (PNES) represent a serious challenge for the clinicians. However, the frequency, associations, and outcomes of dual diagnosis of epilepsy and PNES are unclear. The aim of the review was to determine the frequency, correlates, and outcomes of a dual diagnosis. A systematic review of all published observational studies (from inception to Dec. 2016) was conducted to determine the frequency, correlates, and outcomes of dual diagnosis. We included studies of individuals of any age reporting a dual diagnosis of epilepsy and PNES. All observational study designs were included with the exception of case reports and case series with fewer than 10 participants. The mean frequency of epilepsy in patients with PNES across all studies was 22% (95% confidence intervals [CI] 20 to 25%, range: 0% to 90%) while the mean frequency of PNES in patients with epilepsy was 12% (95% CI 10 to 14%, range: 1% to 62%). High heterogeneity means that these pooled estimates should be viewed with caution. A number of correlates of dual diagnosis were reported. Some studies delineated differences in semiology of seizures in patients with dual diagnosis vs. PNES or epilepsy only. However, most of the correlates were inconclusive. Only a few studies examined outcome in patients with dual diagnosis. Dual diagnosis is common in clinical practice, especially among patients referred to specialized services, and requires careful diagnosis and management.

[French guidelines on electroencephalogram]

Electroencephalography allows the functional analysis of electrical brain cortical activity and is the gold standard for analyzing electrophysiological processes involved in epilepsy but also in several other dysfunctions of the central nervous system. Morphological imaging yields complementary data, yet it cannot replace the essential functional analysis tool that is EEG. Furthermore, EEG has the great advantage of being non-invasive, easy to perform and allows control tests when follow-up is necessary, even at the patient's bedside. Faced with the advances in knowledge, techniques and indications, the Société de Neurophysiologie Clinique de Langue Française (SNCLF) and the Ligue Française Contre l'Épilepsie (LFCE) found it necessary to provide an update on EEG recommendations. This article will review the methodology applied to this work, refine the various topics detailed in the following chapters. It will go over the summary of recommendations for each of these chapters and underline proposals for writing an EEG report. Some questions could not be answered by the review of the literature; in those cases, an expert advice was given by the working and reading groups in addition to the guidelines.

Epilepsy in the elderly: facts and challenges

The incidence of epilepsy in the elderly has increased steadily over the last few decades. In some industrialized countries, one-third of the population is expected to be over the age of 65 in 2030. Therefore, we will face a dramatic increase in the number of elderly patients with epilepsy, many of whom will likely present comorbidities. This increase will put a heavy burden on health care and pension systems. This article focuses on epidemiology, diagnosis and treatment in epilepsies in the elderlies and outlines current research as well as future requirements for research. The diagnosis of epilepsy in the elderly can be difficult and may require long-term video-EEG monitoring. Stroke is the most frequent etiology in epilepsies in the elderlies. Status epilepticus in acute symptomatic epilepsies often results in fatality and may become an increasing health problem. The article also describes the current strategies in antiepileptic drug treatment and epilepsy surgery in the elderly. Novel antiepileptic drugs are necessary as current antiepileptics have strong interaction potentials and harmful side effects, making them ill-suboptimal for treating epilepsy in the elderly.

A critical appraisal on the utility of long-term video-EEG monitoring in older adults

BACKGROUND

World-over, the majority of patients undergoing video-EEG monitoring (VEM) are in their second or third decades. Although elderly represent the fastest growing segment of population with epilepsy, only few of them undergo VEM. We critically evaluated the utility of VEM in the diagnosis and long-term management of older adults with paroxysmal behavioral events.

METHODS

148 consecutive patients aged 45 and above, who underwent long-term (≥8 h) inpatient VEM from 1996 to 2009 formed the study cohort. Utilizing a structured proforma, we gathered their demographic, clinical, electrophysiological and long-term outcome data. VEM was considered as "useful" when it changed the diagnosis and/or management; it was "corroborative" when it helped the treating physician to confirm the diagnosis and "not useful" when it neither helped to improve the diagnosis nor the management.

RESULTS

The mean age was 51.3 (SD 6.4) years; mean duration of VEM was 69.3 h. Out of 117 patients with a diagnosis of epileptic seizures referred for presurgical evaluation or classification, VEM was "useful" or "corroborative" in 111 patients (94.8%; p=0.0001). It was also "useful" or "corroborative" in 29 out of 31 patients (93.5%) referred with a suspicion of associated or pure psychogenic non-epileptic seizures (p=0.0001). None developed any complications during monitoring. At a mean follow-up of 37.7 months there was significant reduction in AED usage in patients with epilepsy (p=0.0001) and epilepsy with associated PNES (p=0.001). At a mean follow-up of 34.2 months, all patients with pure PNES were event-free and medication-free at last follow-up (p=0.002). Twenty-three patients (19.6%) underwent surgery, all except one remaining seizure-free at a mean follow-up of 39.2 months.

CONCLUSIONS

VEM is a safe and cost-effective investigation strategy in older-adults. It aided in improving the diagnosis, offered better treatment including surgery and helped in excluding non-epileptic paroxysmal events in majority.